• Notes:
    1. AY2017/2018 Semester 2, AY2018/2019 Semester 2, bidding data not available.
    2. The bidding statistics are highly non-normal, likely due to being bounded by zero (they cannot bid negative points or have negative bidders). May consider using zero-inflated or poisson regression if considering these statistics as dependent variables.

1 Phase 1: Setting Up Environment, Packages And Loading Data.

1.3 >>Load myBid.RDS

1.5 >>Load myModInfo.RDS

2 Phase 2: Filter, Transform And Merge Data

3 Phase 3: Data Diagnostics

  • Plot univariate histograms and bivariate plots using loops for almost every combination of variables.
  • The graphs from this section are predominantly for diagnostics rather than exploration, what I mean is that the graphs from this section would make little sense if one tried to draw insights from them. This is because they are aggregated across all other variables.
    • For example: The mean of Bidders is calculated across all academic years, all bidding rounds, all modules…
  • What I am looking out for in this section are odd patterns, like zeroes in places where they shouldn’t be, missing data, highly non-normal data, variables with outliers, etc…

3.1 Univariate Descriptive Statistics

##    ModuleCode        AcadYear   Semester Round        Quota           Bidders         LowestBid       LowestSuccessfulBid   HighestBid                                    StudentAcctType   StartTime         DayText   
##  PL1101E: 210   2013/2014:404   1:1109   1A:634   Min.   :  1.00   Min.   :  0.00   Min.   :   0.00   Min.   :   0.0      Min.   :   0.0   New Students [P]                       : 314   Min.   : 800   Monday   :380  
##  PL3232 :  74   2015/2016:384   2:1097   1B:389   1st Qu.:  4.00   1st Qu.:  1.00   1st Qu.:   1.00   1st Qu.:   1.0      1st Qu.:   1.0   NUS Students [P]                       : 331   1st Qu.:1100   Tuesday  :461  
##  PL3236 :  72   2014/2015:349            1C:244   Median : 16.00   Median :  3.00   Median :   1.00   Median :   1.0      Median : 301.0   Returning Students [P]                 :1191   Median :1300   Wednesday:558  
##  PL3235 :  71   2016/2017:272            2A:300   Mean   : 26.87   Mean   : 13.43   Mean   :  69.75   Mean   : 233.3      Mean   : 700.4   Returning Students and New Students [P]: 370   Mean   :1306   Thursday :493  
##  PL3234 :  70   2012/2013:263            2B:308   3rd Qu.: 32.00   3rd Qu.:  9.00   3rd Qu.:   5.00   3rd Qu.: 101.0      3rd Qu.:1173.8                                                  3rd Qu.:1500   Friday   :314  
##  PL3233 :  67   2011/2012:194            3A:173   Max.   :430.00   Max.   :440.00   Max.   :2430.00   Max.   :3459.0      Max.   :4801.0                                                  Max.   :1900                  
##  (Other):1642   (Other)  :340            3B:158

3.3 Bivariate Plots

3.3.4 Continuous-Categorical

## AcadYear ~ Quota

## AcadYear ~ Bidders

## AcadYear ~ LowestBid

## AcadYear ~ LowestSuccessfulBid

## AcadYear ~ HighestBid

## AcadYear ~ StartTime

## Semester ~ Quota

## Semester ~ Bidders

## Semester ~ LowestBid

## Semester ~ LowestSuccessfulBid

## Semester ~ HighestBid

## Semester ~ StartTime

## Round ~ Quota

## Round ~ Bidders

## Round ~ LowestBid

## Round ~ LowestSuccessfulBid

## Round ~ HighestBid

## Round ~ StartTime

## StudentAcctType ~ Quota

## StudentAcctType ~ Bidders

## StudentAcctType ~ LowestBid

## StudentAcctType ~ LowestSuccessfulBid

## StudentAcctType ~ HighestBid

## StudentAcctType ~ StartTime

## DayText ~ Quota

## DayText ~ Bidders

## DayText ~ LowestBid

## DayText ~ LowestSuccessfulBid

## DayText ~ HighestBid

## DayText ~ StartTime